Test growroot in boot tests

Test that we see the root partition grow.

Increase the root disk size to 5gb, and check that the booted vm has
grown the disk to at least that.  Add disk size tracking so we can
more clearly see what's being built into the images.

Change-Id: I377beffc4896e03f0c2d01c0061c5f8652e8b1d1
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

tools/check_devstack_plugin.sh

@@ -2,6 +2,9 @@
 
 LOGDIR=$1
 
+# Set to indiciate an error return
+RETURN=0
+
 NODEPOOL_INSTALL=${NODEPOOL_INSTALL:-/opt/stack/nodepool-venv}
 NODEPOOL_CONFIG=${NODEPOOL_CONFIG:-/etc/nodepool/nodepool.yaml}
 NODEPOOL_SECURE=${NODEPOOL_SECURE:-/etc/nodepool/secure.conf}
@@ -32,6 +35,15 @@ function sshintonode {
 
     node=`$NODEPOOL list | grep $name | grep $state | cut -d '|' -f6 | tr -d ' '`
     /tmp/ssh_wrapper $node ls /
+
+    # Check that the root partition grew on boot; it should be a 5GiB
+    # partition, but subtract some space for boot region.
+    root_size=$(/tmp/ssh_wrapper $node -- lsblk -rbno SIZE /dev/vda1)
+    expected_root_size=$(( (5 * 1024 * 1024 * 1024) - ( 2048 * 1024 ) ))
+    if [[ $root_size -lt $expected_root_size ]]; then
+        echo "Root device does not appear to have grown: $root_size"
+        RETURN=1
+    fi
 }
 
 function waitforimage {
@@ -153,3 +165,5 @@ $NODEPOOL delete --now 0000000000
 
 # show the deleted nodes (and their replacements may be building)
 $NODEPOOL list
+
+exit $RETURN